of cleveland



July 9, 1929.

F. E. LOU DY AIRPLANE Filed Sept. 15, 1927 2 Sheets-Sheet 1 INVENTOR Patented July 9, 1929.

UNITED STATES PATENT OFFICE.

FLAVIUS E. LOUDY, OF CLEVELAND, OHIO, ASSIGNOR TO THE GLENN L. MARTIN COM- PANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

AIRPLANE.

Application filed September 15, 1927.

This invention relates to improvements in airplanes, having reference particularly to improved means for controlling the ailerons of an airplane, and has special utility when applied to airplanes in which the wings or portions of the wings may be folded back- Wardly when the plane is not 1n 1186 111 order to conserve hangar space or ItICIlItZItG thQ storage of planes in ships or other carriers.

One of the objects of the invention 1s the provision of a separable joint in the aileron control element or elements, one portion of each joint being carried by the swinging part of the wing and the other by the fired part, these portions engaging when the wing is in the operative position and actlng at such times to transmit motion of the control elements across the joint.

Another object of the invention is the provision of means for producing a differential control of the ailerons on opposite sides of the airplane, and particularly the provision of a differential control which may be incorporated in the separable joint above referred to.

A further object of the invention is the provision of means for locking the ailerons against movement when the wings are swung backwardly out of operative position, thus preventing possible damage from having the ailerons drag upon the ground or against high spots on the ground.

Still another object is the prevention of unequal tightening and slackening of the cables, which is present in the usual hook-up due to the swinging of the aileron mast about a center located forward of the mast.

Other objects and features of novelty, particularly such as relate to details of construction, will appear as I proceed with the description of that embodiment of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawings, in which:

Fig. 1 is a diagrammatic view in perspective, illustrating my invention as applied to one wing of an airplane;

Fig. 2 is a detail plan view showing the lever mechanism at one of the wing joints, with the parts in the position which they assume when the aileron for that wing is tilted downwardly to raise that side of the plane;

Serial No. 219,640.

Fig. 3 is a plan view of the same mechanism in neutral position; and

Fig. 4 is a plan View of the same mechanism in the position which it occupies when the corresponding aileron is tilted upwardly to depress that side of the plane.

Similar reference characters refer to like parts throughout the views.

Referring first to Fig. 1, parts of the rear wing beam are indicated at 10 and 11, being connected by a vertical hinge 12. The outer portion of the wing of the airplane is adapted to swing back on this hinge 12 into inoperative position after the forward edge is unlocked by means to be referred to hereinafter. A portion of the aileron is shown at 13, having a mast let projecting upwardly and downwardly therefrom. The aileron is pivotally mounted in a conventional manner along an axis just in advance of the line 15.

Through the fuselage of the airplane aileron control elements 16, 17 and 18 extend. lVhile I do not desire to be limited to the use of cables, I have adopted cables for purposes of illustration in the present instance, and as means for actuating the same I have illustrated a wheel 19 provided with a sprocket 20 over which runs a chain 21 that is attached to the cables 16 and 17, the latter running over aligned sheaves 22 and 23 positioned below the sprocket 20.

The joint between the two portions of the wing is indicated in Fig. 1 by the dot and dash line 2 1, while in Figs. 2, 3 and at it is indicated by the two dot and dash lines 24:. For the sake of clearness, the forward wing beam is not illustrated in Fig. 1, but the two parts of this beam are indicated at 25 and 26 in Figs. 2, 3 and 4:, 25 being the inboard part and 26 the outboard part of the beam. These two parts overlap and are provided with vertical openings which register when the wing is in operative position, and in this position receive a pin 27 by means of which the two parts are firmly locked together, thus preventing movement of the outer wing part about the hinge 12.

In the beam part 25, there is fixed a vertical pin 28 upon which is journaled an upper lever 29 of angular shape and a lower lever 30 of similar shape, these two levers being independently movable upon the pin 28. At their forward ends they are provided with openings in which may be mounted the attaching means for the cables 17 and 18 respectively. Their rear ends are preferably provided with anti-friction wheels or rollers 31.

In the beam part 26 there is mounted a pin 32 similar to the pin 28, upon which are journaled an upper lever 33 and a lower lever 34, the lever 33 being at the same level the lever 29 and adapted to engage the roller 31 thereof and the lever 34 being at the same level as the lever 30 and adapted to engage the roller 31 thereof. The surfaces upon the levers 33 and 34, which are adapted to engage the rollers 31 of the levers 9.!) and 30 respectively, are cams with reversely curved faces. The engaging face of lever is such that when the for ard end of lever 29 is positioned at a given angle A to the left of neutral, as shown in Fig. .2, the forward end of lever 33 will be positioned at a relatively small angle B to the left of neutral, but when the forward end of lever 29 is positioned at an angle A to the right of neutral, as shown in Fig. 4, the forward end of lever 33 will be positioned at angle C to the right of neutral, the angle C being greater than the angle 15. In other words, the mutual elli'eet of the lovers upon each other is different when they move from neutral in one direction than when they move from neutral in the opposite direction. The engaging surface of the lever 34, however, is such that when the forward end of lever 30 is positioned at angle A to the left of neutral, as :in Fig. 4, the forward end of lever 34 is at angle C to the left of neutral, while when lever 30 is at angle A to the right of neutral, as in Fig. 2, lever 34 is at angle B to the right of neutral. Hence the movement of lever 25.) to the left swings lever 33 through the smaller angle while the movement of lever 30 to the left permits lever 34 to be swung through the larger angle. The opposite effects are true when the levers are swung toward the right.

On the side of the plane opposite that illustrated in Fig. 1, the levers are identical with those illustrated herein except that they are oppositely arranged, that is, they are symmetrical about the central vertical. longitudinal plane of the machine, the upper lever 29 and the lower lever 30 being on the inboard side and the upper lever 33 and the lower lever 34 being on the outboard side. The levers 33 and 34 on each side of the plane are provided with openings 35 and 36 which are of correct size to receive the pins 27. Hence, when the wings are to be folded, the pins 27 are removed from the aligned openings in the beam parts 25 and 26 and are placed in the openings 35 and 36 and an opening in a portion 37 of each wing lying between the levers. Thus the wings are unlocked and the lovers 33 and 34 are locked together and to the wing. On each side of the plane, the forward end o l lever 33 is connected by a cable 38 with the upper extremity of mast 14, and the forward end of lever 34 is connected with the lower extremity of that mast by a cable 39, these cables passing over sheaves 40 and 41 respectively.

0 perm/1022..

Assume that the operator desires to tilt aileron 13 upwardly and the aileron on the other side of the machine in a reverse direction. The wheel 19 is turned so as to pull cable 17 to the left, as viewed in Fig. l, or to the right as viewed in the rcmaining figures. The lever 29 then swings from neutral position, illustrated. in Fig. 3, through a certain angle dependent upon the angle through which the wheel 15) turned. Assume that this angle is the angle A. in other words, that lever 29 takes the position shown in Fig. 4. The lever 33, by virtue of its engagement with the lever 29, is swung in the same direction through an angle 0. The cable 38 is thereby pulled and the aileron 13 tilted upwardly. This puts a, pull upon cable 39 in the opposite direction and causes lever 34 to swing in a direction opposite to that of lever 33, but through the same angle C, as indicated in Fig. 4. Lever 30 is thereby swung through an angle A in a direction opposite to that of lever 25). thereby pulling upon cable 13 and moving that cable a distance equal to the movementof cable 17 but in the opposite direction.

On the opposite side of the airplane, the cable 18 swings its lever 30 through angle A and the lever 34 on that side through angle B. Angle B is smaller than angle (1-, and hence the pull upon the cable 39 on that side of the machine is less and the downward tilting of the aileron on that side is through a smaller angle than that through which the aileron 13 is upwardly tilted. The downward tilting of the unillnstrated aileron produces an outward pull upon the cable 38 on that side, which pull is communicated through the levers 34 and 30 on that side swinging the .lever 3) through angle A and thus. comn'uinicating a pull to cable 16 in a direction to take up the slack which tends to form in, cable 16 caused by the turning of the wheel 19, as previously described. The uptilting of one aileron is, therefore, greater than the down-tilting of the opposite aileron, this being desirable because of the fact that an aileron tilting downwardly through a given angle produces a greater drag than an aileron tilted upwardly through the same angle. The degree of differential action may be varied by the design of the lovers, that which I prefer being 100%, that is, an uptilting twice that of the down-tilting. When the wheel is turned in the opposite direction, the differential action also takes place in the opposite direction, as will be apparent from a study of the construction.

Owing to the fact that, as the mast 14c swings out of normal position its ends move inward, while the sheaves 40 and 41 remain fixed, the lengths of cables 38 and 39 between the mast and the sheaves vary slightly as the mast swings. This effect is cumulative on the opposite side of the plane, and results in a slack condition in part of the cable, speaking now of the conventional hook-up. I11 my invention, however, the cam surfaces of the levers and 34: may be so laid. out that this objectionable slack will be taken up in all positions of the ailerons. This feature of the invention is of considerable importance.

I-Iaving thus described my invention, I claim:

1. In an airplane, a jointed wing comprising a hinge near one edge thereof, an aileron control comprising two levers pivoted to the wing one on each side of said joint, the cor responding ends of said levers being adapted to be connected with control elements on opposite sides of said joint, and the opposite ends of the levers being adapted to engage each other when the wing is in operative position, the arrangement of the lever parts being non-symmetrical, whereby the movement of the connection end of one lever through a certain distance produces in the connection end of the other lever a movement through a different distance.

2. In an airplane, a differential aileron control comprising two levers pivotally mounted adjacent each other, and aileron control elements connected to said levers, said levers having interengaging portions, the arrangement of the lever parts being non-symmetrical, whereby the movement of one control element through a certain distance produces in the other control element a movement through a different distance.

3. In an airplane, an aileron control comprising two levers pivotally mounted adjacent each other, and aileron control elements connected to said levers, said levers having interengaging portions and being so designed and arranged with respect to each other that as one control element moves from a given angle on one side of neutral to an equal angle on the other side of neutral the second lever will move from a given angle on one side of neutral to a different angle on the other side of neutral.

4. In an airplane, a wing having a portion thereof hinged to swing backwardly, an aileron on said wing, a pair of aileron control cables on said hinged portion movable in opposite directions as the aileron swings about its pivot, a pair of lovers to which the inner ends of said cables are connected, and means for securing said levers to the hinged wing portion, whereby the aileron is locked against movement.

5. In an airplane, a wing having a portion thereof hinged to swing baclnvardly, an aileron on said wing, the fixed and swinging portions of said wing having openings therein aligning when the wing is in operative position, a pin adapted to fit said openings, a pair of aileron control cables on said hinged wing portion, said cables being movable in opposite directions as the aileron swings about its pivot, a pair of levers mounted one above the other to which said cables are connected, said levers having openings therethrongh adapted to register with an opening in the hinged wing portion and to receive said pin, whereby the aileron is locked against movement.

6. In an airplane, a jointed wing comprising a hinge near one edge thereof, an aileron control comprising a pair of cables divided at the joint of the wing, two levers pivoted to the wing one on each side of said joint, said levers having corresponding ends secured tothe divided portions of one of said cables, two other levers similarly connected to the divided portions of the other cable, the ends of each pair of levers opposite the cable attachments being disposed to engage each other when the wing is in operative position, whereby the movement of the cables on one side of the joint is transmitted to the divided portions thereof on the other side of the joint.

In testimony whereof, I hereunto affix my signature.

FLAVIUS E. LOUDY. 

